fix some file extensions

Task/Nth-root/CoffeeScript/nth-root-1.coffee

@@ -0,0 +1,26 @@
+nth_root = (A, n, precision=0.0000000000001) ->
+  x = 1
+  while true
+    x_new = (1 / n) * ((n - 1) * x + A / Math.pow(x, n - 1))
+    return x_new if Math.abs(x_new - x) < precision
+    x = x_new
+
+# tests
+do ->
+  tests = [
+    [8, 3]
+    [16, 4]
+    [32, 5]
+    [343, 3]
+    [1024, 10]
+    [1000000000, 3]
+    [1000000000, 9]
+    [100, 2]
+    [100, 3]
+    [100, 5]
+    [100, 10]
+  ]
+  for test in tests
+    [x, n] = test
+    root = nth_root x, n
+    console.log "#{x} root #{n} = #{root} (root^#{n} = #{Math.pow root, n})"